Revert "Bump up CI dependency versions"

This reverts commit 9124d80.

.github/workflows/ci.yml

@@ -13,8 +13,8 @@ jobs:
       _R_CHECK_CRAN_INCOMING_REMOTE_: false
 
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
         with:
           python-version: '3.9'
       - uses: actions/setup-dotnet@v1
@@ -24,9 +24,9 @@ jobs:
         with:
           r-version: '4'
       - uses: r-lib/actions/setup-pandoc@v1
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v2
         with:
-          node-version: 20
+          node-version: '16'
 
       - name: Install python dependecies
         run: pip install cffi numba pytest
@@ -43,7 +43,7 @@ jobs:
         working-directory: ./src/r
         shell: Rscript {0}
       - name: Cache R packages
-        uses: actions/cache@v4
+        uses: actions/cache@v2
         with:
           path: ${{ env.R_LIBS_USER }}
           key: ${{ runner.os }}-${{ hashFiles('src/r/.github/R-version') }}-1-${{ hashFiles('src/r/.github/depends.Rds') }}
@@ -80,8 +80,8 @@ jobs:
   gh-pages:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-python@v5
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
       with:
         python-version: 3.8